U.S. patent number 5,457,208 [Application Number 08/080,287] was granted by the patent office on 1995-10-10 for kappa opioid receptor antagonists.
This patent grant is currently assigned to Regents of the University of Minnesota. Invention is credited to Sandra L. Olmsted, Philip S. Portoghese.
United States Patent |
5,457,208 |
Portoghese , et al. |
October 10, 1995 |
**Please see images for:
( Certificate of Correction ) ** |
Kappa opioid receptor antagonists
Abstract
Compounds of the formula: ##STR1## are provided, which are
selective kappa opioid receptor antagonists, wherein R.sup.1 is
(C.sub.1 -C.sub.5)alkyl, C.sub.3 -C.sub.6 (cycloalkyl)alkyl,
C.sub.5 -C.sub.7 (cycloalkenyl)alkyl, (C.sub.6 -C.sub.12)aryl,
(C.sub.6 -C.sub.12)aralkyl, trans (C.sub.4 -C.sub.5) alkenyl, allyl
or furan-2-ylalkyl; R.sup.2 is H, OH or O.sub.2 C(C.sub.1
-C.sub.5)alkyl; R.sup.3 is H, (C.sub.6 -C.sub.10)aralkyl, (C.sub.1
-C.sub.5)alkyl or (C.sub.1 -C.sub.5)alkylCO; X is O, S or NY,
wherein Y is H or (C.sub.1 -C.sub.5)alkyl; R.sup.4 is CH.sub.2
(methylene) or C.dbd.O (carbonyl), R.sup.5 is CH.sub.2, C.dbd.O or
C.dbd.NH (imino) and R.sup.6 is (C.sub.1 -C.sub.4)alkyl or
NH(C.sub.1 -C.sub.4)alkyl, optionally substituted by a non-terminal
(C.sub.1 -C.sub.2)alkyl group or by N(R.sup.7) (R.sup.8) wherein
R.sup.7 and R.sup.8 are individually H or (C.sub.1 -C.sub.3) alkyl,
with the proviso that one of R.sup.4 or R.sup.5 is CH.sub.2, and
the pharmaceutically acceptable salts thereof.
Inventors: |
Portoghese; Philip S. (St.
Paul, MN), Olmsted; Sandra L. (Richfield, MN) |
Assignee: |
Regents of the University of
Minnesota (Minneapolis, MN)
|
Family
ID: |
22156419 |
Appl.
No.: |
08/080,287 |
Filed: |
June 21, 1993 |
Current U.S.
Class: |
546/35 |
Current CPC
Class: |
C07D
489/06 (20130101) |
Current International
Class: |
C07D
489/06 (20060101); C07D 489/00 (20060101); C07D
489/06 (); A61K 031/44 () |
Field of
Search: |
;514/279 ;546/35 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Department of Health, Education and Welfare, Public Health Service,
Grant Application Nos. DA 1533-01 (Jun. 23, 1976); May 11, 1977
(02); May 10, 1978 (03); May 30, 1979 (04); Jul. 17, 1980 (05); May
26, 1981 (06); Jun. 2, 1982 (07); Jun. 13, 1983 (08); May 10, 1984
(09); May 31, 1985 (10); Jun. 9, 1986 (11); (not dated) (12); (not
dated) (13); Not complete (pp 31-34 omitted) (14); May 31, 1990
(15); May 29, 1991 (16); and Mar. 26, 1992 (17). .
J. C. Froehlich et al., "Naloxon Attenuates Voluntary Ethanol
Intake in Rats Selectively Bred for High Ethanol Preference",
Pharm. Biochem. Behav., 35, 385 (1990). .
J. C. Froehlich et al., "Importance of Delta Opioid Receptors in
Maintaining High Alcohol Drinking", Psychopharmacol., 103, 467
(1991). .
M. Gates et al., "Some Potent Morphine Antagonists Possessing High
Analgesic Activity", J. Med. Chem., 7, 127 (1964). .
G. Henderson et al., "A New Example of a Morphine-Sensitive
Neuro-Effector Junction: Adrenergic Transmission in the Mouse Vas
Deferens", Brit. J. Pharmacol., 46, 764-766 (1972). .
W. R. Martin, "Pharmacology of Opioids", Pharmacol. Rev., 35,
283-323 (1983). .
S. L. Olmsted et al., "A Remarkable Change of Opioid Receptor
Selectivity on the Attachment of a Peptidomimetic kappa Address
Element to the delta Antagonist, Natrindole", J. Med. Chem., 36,
179-180 (1993). .
P. S. Portoghese et al., "Application of the Message Address
Concept in the Design of Highly Potent and Selective Non-Peptide
delta Opioid Receptor Antagonists", J. Med. Chem., 31, 281 (1988).
.
P. S. Portoghese et al., "Only One Pharmacophore is Required for
the kappa Opioid Antagonist Selectivity of Norbinaltorphimine", J.
Med. Chem., 31, 1344 (1988). .
P. S. Portoghese et al., "Bivalent Ligands and the Message-Address
Concept in the Design of Selective Opioid Receptor Antagonists",
Trends Pharmacol. Sci., 10, 230 (1989). .
P. S. Portoghese et al., "Design of Peptidomimetic delta Opioid
Receptor Antagonists Using the Message-Address Concept", J. Med.
Chem., 33, 1714 (1990). .
R. J. Roon et al., "Synthesis of Quisqualic Acid Analogues as
Possible Selective Ligands at Quisqualic Acid Receptors", Soc.
Neuroscience Abstracts, 18, 649 Abstract No. 277.16 (1992). .
M. Sofuoglu et al., "Differential Antagonism of delta Opioid
Agonists by Naltrindole and its Benzofuran Analog (NTB) in Mice:
Evidence for delta Opioid Receptor Subtypes", J. Pharmacol. Exp.
Ther., 257, 676 (1991). .
N. Subasinghe et al., "Synthesis of Quisqualic Acid Analogues as
Possible Selective Ligands at Quisqualic Acid Receptors", 23rd
National Medicinal Chemistry Symposium, Buffalo N.Y., Abstract No.
12 (1992). .
N. Subasinghe et al., "Quisqualic Acid Analogues: Snythesis of
beta-Heterocyclic 2-Aminopropanoic Acid Derivatives and Their
Activity at a Novel Quisqualate-Sensitized Site", J. Med. Chem.,
35, 4602-2607 (1992). .
J. R. Volpicelli et al., Opioids, Bulimia and Alcohol Abuse and
Alcoholism, L. D. Reid, ed., Springer-Verlat at pp. 195-214 (1990).
.
S. Ward, "Improved Assays for the Assessment of kappa and delta
-Properties of Opioid Ligands", Eur. J. Pharmacol., 85, 163 (1982).
.
L. Werling et al., "Opioid binding to Rat and Guinea Pig Neural
Membranes in the Presence of Physiological Cations at 37.degree.
C.", J. Pharmacol. Exp. Ther., 233 722 (1985)..
|
Primary Examiner: Daus; Donald G.
Attorney, Agent or Firm: Schwegman, Lundberg &
Woessner
Government Interests
BACKGROUND OF THE INVENTION
This invention was made with the assistance of the Government under
a grant from the National Institutes of Health (Grant No. DA
01533). The U.S. Government has certain rights in the invention.
Claims
What is claimed is:
1. A compound of the formula: ##STR19## wherein R is the moiety
R.sup.4 -NHR.sup.5 -R.sup.6, wherein R.sup.4 is CH.sub.2 or
C.dbd.O, R.sup.5 is CH.sub.2, C.dbd.O, or C.dbd.NH and R.sup.6 is
(C.sub.1 -C.sub.4)alkyl, optionally substituted by a non-terminal
(C.sub.1 -C.sub.4)alkyl group or by N(R.sup.7) (R.sup.8), wherein
R.sup.7 and R.sup.8 are individually H or (C.sub.1 -C.sub.3)alkyl,
with the proviso that when R.sup.4 is C.dbd.O, R.sup.6 is
substituted with N(R.sup.7)(R.sup.8), and with the proviso that one
of R.sup.4 or R.sup.5 is CH.sub.2, and the pharmaceutically
acceptable salts thereof.
2. A compound of claim 1 wherein R.sup.4 is CH.sub.2.
3. A compound of claim 2 wherein R.sup.5 is C.dbd.NH.
4. A compound of claim 3 wherein R.sup.6 is methyl, ethyl, propyl,
butyl or 2-methyl-butyl.
5. A compound of claim 3 wherein R.sup.7 and R.sup.8 both are
methyl or ethyl.
6. A compound of claim 5 wherein R.sup.6 is dimethylaminomethyl or
dimethylaminopropyl.
7. A compound of claim 1 wherein R.sup.4 is C.dbd.O and R.sup.5 is
CH.sub.2.
8. A compound of claim 7 wherein R.sup.7 and R.sup.8 both are
methyl or ethyl.
9. A compound of claim 8 wherein R.sup.6 is dimethylaminomethyl or
diethylaminomethyl.
10. A compound of claim 1 wherein R.sup.4 is CH.sub.2 and R.sup.5
is C.dbd.O.
11. A compound of claim 10 wherein R.sup.7 and R.sup.8 both are
methyl or ethyl.
12. A compound of claim 11 wherein R.sup.6 is dimethylaminoethyl.
Description
Endogenous opioid peptides are involved in the mediation or
modulation of a variety of mammalian physiological processes, many
of which are mimicked by opiates or other non-endogenous opioid
ligands. Some of the effects that have been investigated are
analgesia, tolerance and dependence, appetite, renal function,
gastrointestinal motility, gastric secretion, learning and memory,
mental illness, epileptic seizures and other neurological
disorders, cardiovascular responses, and respiratory
depression.
The fact that the effects of endogenous and exogenous opioids are
mediated by at least three different types [mu (.mu.), delta
(.delta.), kappa (.kappa.)] of opioid receptors raises the
possibility that highly selective exogenous opioid agonist or
antagonist ligands might have therapeutic applications. See W. R.
Martin, Pharmacol. Rev., 35, 283 (1983). Thus, if a ligand acts at
a single opioid receptor type or subtype, the potential side
effects mediated through other opioid receptor types can be
minimized or eliminated.
The prototypical opioid antagonists, naloxone and naltrexone, are
used primarily as pharmacologic research tools and for the reversal
of toxic effects of opioids in case of overdose. Since these
antagonists act at multiple opioid receptors, their applications in
other therapeutic areas or as pharmacologic tools appear to be
limited. However, naltrexone recently was reported to reduce the
incidence of relapse in recovering alcoholics by J. R. Volpicelli
et al., Opioids, Bulimia and Alcohol Abuse and Alcoholism, L. D.
Reid, ed., Springer-Verlag (1990) at pages 195-214. Naloxone has
been reported to suppress ethanol but not water intake in a rat
model of alcoholism. J. C. Froehlich et al., Pharm. Biochem.
Behav., 35, 385 (1990).
Some progress has been made in the development of highly selective
opioid antagonists. For example, Portoghese et al. (U.S. Pat. No.
4,816,586) disclose certain opiate analogs which possess high
selectivity and potency at delta receptors. Minimal involvement was
observed at mu and kappa opioid receptors. One of the highly
selective analogs disclosed in U.S. Pat. No. 4,816,586 has been
named "naltrindole" or "NTI," and has the formula: ##STR2## wherein
X is NH. See P. S. Portoghese et al., J. Med. Chem., 31, 281
(1988).
Portoghese et al. (U.S. Pat. No. 4,649,200) disclose substituted
pyrroles which exhibit selective antagonism at kappa opioid
receptors. One such analog is norbinaltrophimine (norBNI), which
has the formula: ##STR3## The selectivities of these prototypical
.delta. and .kappa. opioid receptor antagonists have been
attributed to the presence of nonpeptide "address" mimics which
bear a functional relationship to key elements in the putative
.delta. and .kappa. addresses of enkephalin and dynorphin,
respectively. See, P. S. Portoghese et al., Trends Pharmacol. Sci.,
10, 230 (1989). Accordingly, the design of NTI employed a model
that envisaged the Phe.sup.4 phenyl group of enkephalin as a
critical part of the .delta. address. See, P. S. Portoghese et al.,
J. Med. Chem., 33, 1714 (1990). Similarly, the address element
conferring selectivity in norBNI has been suggested to be a basic
function that mimics the guanidinium moiety of Arg.sup.7 in
dymorphin, by P. S. Portoghese et al., J. Med. Chem., 31, 1344
(1988).
It has recently been reported that suppression of ethanol ingestion
may be mediated by the delta opioid receptor type. For example, the
.delta. antagonist, N,N-diallyl-Tyr-Aib-Aib-Phe-Leu-OH (ICI
174864), strongly inhibits ethanol drinking, but has a very short
duration of action, which may limit its clinical utility. See J. C.
Froehlich et al., Psychopharmacol., 103, 467 (1991). Using NTI as
an antagonist, M. Sofuoglu et al., J. Pharmacol. Exp. Ther.,
257,676 (1991) determined that the antinociceptive activity of two
delta receptor agonist enkephalin analogs, DSLET and DPDPE, may be
mediated by two discrete delta opioid receptor subtypes. It has
also been suggested that development of addiction and/or tolerance
to opiates may be inhibited by delta-opioid receptor antagonists,
and that opioid-type delta-opioid receptor antagonists may be
useful as immunosuppressive agents. Likewise, compounds which are
selective at mu receptors may be useful as analgesics which do not
exhibit the potentially harmful side effects of less-selective
analgesics such as morphine.
Therefore, a continuing need exists for compounds which are opioid
receptor-selective, i.e., which can act as agonists or antagonists
with specificity at the delta, mu or kappa opioid receptor, or at
one of the subtypes of these receptors.
SUMMARY OF THE INVENTION
The present invention is directed to biologically active compounds
of formula (I): ##STR4## wherein R.sup.1 is (C.sub.1 -C.sub.5 )
alkyl, C.sub.3 -C.sub.6 (cycloalkyl) alkyl, C.sub.5 -C.sub.7
(cycloalkenyl)alkyl, (C.sub.6 -C.sub.12)aryl, (C.sub.7
-C.sub.12)aralkyl, trans(C.sub.4 -C.sub.5)alkenyl, allyl or
furan-2-ylalkyl, R.sup.2 is H, OH or O.sub.2 C(C.sub.1
-C.sub.5)alkyl; R.sup.3 is H, (C.sub.7 -C.sub.10)aralkyl, (C.sub.1
-C.sub.5)alkyl or (C.sub.1 -C.sub.5)alkylCO; X is O, S or NY,
wherein Y is H or (C.sub.1 -C.sub.5)alkyl; R.sup.4 is CH.sub.2
(methylene) or C.dbd.O (carbonyl), R.sup.5 is CH.sub.2, C.dbd.O or
C.dbd.NH (imino) and R.sup.6 is (C.sub.1 -C.sub.4)alkyl or
NH(C.sub.1 -C.sub.4)alkyl, optionally substituted by a non-terminal
(C.sub.1 -C.sub.2)alkyl group or by N(R.sup.7) (R.sup.8) wherein
R.sup.7 and R.sup.8 are individually H or (C.sub.1 -C.sub.3)alkyl,
with the proviso that one of R.sup.4 or R.sup. 5 is CH.sub.2, and
the pharmaceutically acceptable salts thereof.
Using peptide antagonists of known binding selectivity as
standards, it was unexpectedly found that the compounds of the
invention are selective antagonists at kappa opioid receptors,
while exhibiting little or no binding at delta or mu receptors.
Thus, the present invention also provides a method for blocking
kappa opioid receptors in mammalian tissue comprising contacting
said receptors in vivo or in vitro with an effective amount of the
compound of formula I, preferably in combination with a
pharmaceutically acceptable vehicle. Thus, the compounds of formula
I can be used as pharmacological and biochemical probes of opiate
receptor structure and function, e.g., to measure the selectivity
of other known or suspected opioid receptor antagonists or
agonists. Such tissue includes tissue of the central nervous system
(CNS), the gut, the cardiovascular system, the lung, the kidney,
reproductive tract tissue and the like. Therefore, the compounds of
formula I which exhibit kappa receptor antagonist activity may also
be therapeutically useful in conditions where selective blockage of
kappa receptors is desired. This includes blockage of the appetite
response, blockage of paralysis due to spinal trauma and a variety
of other physiological activities that may be mediated through
kappa receptors.
The alkyl moiety present in the R.sup.1 group which links the
cycloalkyl, cycloalkenyl, aryl, or furan-2-yl moiety to the basic
nitrogen atom in the compounds of formula I is a lower(alkyl)
group, preferably --(CH.sub.2).sub.n --, wherein n is about 1-5,
most preferably n is 1, e.g., R.sup.1 is C.sub.3 -C.sub.6
(cycloalkyl)methyl, C.sub.5 -C.sub.7 (cycloalkenyl)methyl,
arylmethyl or furan-2-yl-methyl. Preferred aryl moieties include
(C.sub.6 -C.sub.10)aryl, i.e., phenyl, benzyl, tolyl, napthyl,
xylyl, anisyl and the like.
In structure I, a bond designated by a wedged or darkened line
indicates one extending above the plane of the R.sup.3
O-substituted phenyl ring. A bond designated by a broken line
indicates one extending below the plane of the phenyl ring.
Preferred compounds of the formula I are those wherein R.sup.1 is
(C.sub.1 -C.sub.5)alkyl, C.sub.3 -C.sub.6 (cycloalkyl)alkyl or
C.sub.5 -C.sub.7 (cycloalkenyl)alkyl, preferably wherein R.sup.1 is
C.sub.3 -C.sub.6 (cycloalkyl)methyl, and most preferably wherein
R.sup.1 is cyclopropylmethyl. R.sup.2 is preferably OH or OAc
(O.sub.2 CCH.sub.3), and R.sup.3 preferably is H. Preferably, X is
NH or NCH.sub.3, most preferably NH. Preferably, R.sup.6 is methyl,
ethyl, propyl, butyl or 2-methylbutyl which is unsubstituted or is
terminally substituted with N(CH.sub.3).sub.2 or N (CH.sub.2
CH.sub.3).sub.2. Preferably, R.sup.4 is CH.sub.2 and R.sup.5 is
C.dbd.O or C.dbd.NH.
Since the compounds of the invention are formally morphinan
derivatives, it is believed that their ability to cross the
"blood-brain barrier" and to affect the central nervous system
(CNS) should be far superior to peptide opioid antagonists. For
example, as disclosed in U.S. patent application Ser. No.
07/750,109, filed Aug. 26, 1991, both NTI and its benzofuran
analog, NTB were found to produce unexpectedly prolonged
suppression of ethanol drinking in rats that were selectively bred
for high voluntary ethanol drinking, as compared to peptidyl
delta-opioid receptor antagonists. Processes of preparing the
compounds of formula I are also aspects of the invention, as
described hereinbelow, as are the novel intermediates employed in
the syntheses.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of formula I wherein X is NH can be readily
synthesized by reaction of a 4,5-epoxy-6-ketomorphinan such as
naltrexone (6) with 4-hydrazinobenzonitrile (D. E. Rivett et al.,
Austr. J. Chem., 32 1601 (1979)) under Fischer indole conditions,
as shown in Scheme I, to yield the 5'-nitrile 7. ##STR5## Nitrile 7
was reduced to primary amine 8 using Raney Ni, and 8 was reacted
with the appropriate imidate esters, of the formula CH.sub.3
OC(.dbd.NH)--R, to yield amidates of general formula II, wherein R
is ethyl, 2-methylbutyl, methyl, pentyl, propyl and butyl,
respectively, for compounds 1-6. See, S. R. Sandler et al., Organic
Chemistry, Vol. 3, Academic Press, NY (1972) at pages 268-299; and
E. Cereda et al., J. Med. Chem., 33, 2108 (1990).
Compounds of formula I wherein R.sup.4 is C.dbd.O can be prepared
by reacting a morphinan such as naltrexone with
4-carboxyphenylhydrazine to yield a compound of formula 7 wherein
the 5'-CN group has been replaced by a 5'-carboxy group, i.e.,
compound 15, hereinbelow. The 5'-carboxy intermediate is then
amidated, e.g., with an alkylamine of the formula H.sub.2 NR.sup.5
R.sup.6, wherein R.sup.5 is CH.sub.2 and R.sup.6 is as defined
above, to yield the final products.
Compounds of formula I wherein R.sup.4 is CH.sub.2 and R.sup.5 is
C.dbd.O can be prepared by reacting the 5'-CH.sub.2 NH.sub.2 group,
i.e., of compound 8 with a carboxylic acid of the general formula
HO.sub.2 CR.sup.6 wherein R.sup.6 is as defined above, in the
presence of benzotriazol-1-yloxy-tris(dimethylamino)phosphonium
hexafluorophosphate ("BOP Reagent," Aldrich Chem. Co.).
Compounds of formula I wherein R.sup.4 is CH.sub.2, R.sup.5 is
C.dbd.NH and R.sup.6 is NH(C.sub.1 -C.sub.4)alkyl, optionally
substituted by non-terminal (C.sub.1 -C.sub.2)alkyl or by
N(RT)(R.sup.8) can be prepared by reacting, i.e., a compound of
formula 8 with a compound of the formula R.sup.6 -C(OMe).dbd.NH,
wherein R.sup.6 is as defined immediately above.
Compounds of formula I wherein X is O, S or NY can be prepared from
intermediates analogous to 7 or 8 wherein NH has been replaced by
O, S or NY. These intermediates can be prepared as generally
disclosed in U.S. Pat. No. 4,816,586, which is incorporated by
reference herein, which also discloses methods suitable for the
preparation of salts of compounds of formula I.
The structures, common names and Merck Index reference numbers of
representative 4,5-epoxy-6-ketomorphinan starting materials of
general formula (III) are summarized on Table I, below.
TABLE I ______________________________________ ##STR6## (III)
Common Merck R.sup.1 R.sup.2 R.sup.3 Name No..sup.2
______________________________________ CH.sub.2 CH(CH.sub.2).sub.2
OH H naltrexone 6209 CH.sub.3 OH H oxymorphone 6837 CH.sub.3 H H
hydromorphone 4714 CH.sub.3 H CH.sub.3 hydrocodone 4687 CH.sub.2
CH(CH.sub.2).sub.2 H H -- --.sup.1 CH.sub.2 CHCH.sub.2 OH H
naloxone 6208 CH.sub.3 OH CH.sub.3 oxycodone 6827
______________________________________ .sup.1 Preparation: M. Gates
et al., J. Med. Chem., 7, 127 (1964). .sup.2 The Merck Index, W.
Windholz, ed., Merck & Co., Rahway, NJ (10th ed. 1983).
Other starting materials of the general formula III can be prepared
by synthetic methods which are well known in the art of organic
chemistry. For example, compounds wherein R.sup.1 is H and R.sup.3
is a suitable protecting group, and wherein the 6-keto group has
also been protected, can be prepared from the compounds of formula
III. These intermediates can be N-alkylated and deprotected to
yield compounds of formula I wherein R.sup.1 is C.sub.2 -C.sub.5
(alkyl), C.sub.4 -C.sub.6 (cycloalkyl)alkyl, C.sub.5 C.sub.7
(cycloalkenyl)alkyl, aryl, aralkyl, trans-C.sub.4 -C.sub.5 alkenyl
or furan-2-ylalkyl, by the application of well-known reactions.
For example, the free hydroxyl groups of the compounds of formula
III, e.g., R.sup.2 =OH and/or R.sup.3 =H, can be protected by
acid-labile groups such as tetrahydropyranlyl, trimethylsilyl,
1-methoxy-isopropyl and the like as disclosed in Compendium of
Organic Synthetic Methods, I. T. Harrison et al., eds.,
Wiley-Interscience, New York, N.Y. (1971) at pages 124-131,
(hereinafter "Compendium"). The protection of the 6-keto group of
compounds of Table I by its reversible conversion into a ketal or a
thioketal group is disclosed in Compendium, at pages 449-453.
Methods for the demethylation of N-methyl amines have been
disclosed, for example, in Compendium at page 247, J. Amer. Chem.
Soc., 89, 1942 (1967) and J. Amer. Chem. Soc., 77, 4079 (1955).
Procedures for the alkylation of secondary amines with halides
under basic or neutral conditions are well known. For example, see
Compendium at pages 242-245; Org. Synth., 43, 45 (1963); J. Org.
Chem., 27, 3639 (1962) and J. Amer. Chem. Soc., 82, 6163
(1960).
Compounds of formula III wherein R.sup.2 is acyloxy and/or R.sup.3
is acyl can be prepared by using the corresponding starting
materials on Table I. For example, naltrexone can be diacylated by
reacting it with the appropriate (C.sub.1 -C.sub.5)alkyl anhydride
for 10-18 hrs at 18.degree.-25.degree. C. The resultant
3,14-diacylated compound can be converted to the 14-acylated
compound by limited hydrolysis. The 3-acylated starting materials
can be prepared by the short-term reaction of the compounds of
Table I with the anhydride, e.g., for about 2-4 hours. The
3-acylated product can be separated from the 3,14-diacylated
product by chromatography.
The acid salts of compounds of formula I wherein R.sup.3 =H, can be
converted into the corresponding (C.sub.1 -C.sub.5)alkoxy
derivatives [R.sup.3 =(C.sub.1 -C.sub.5)alkyl] by dissolving the
starting material in DMF and adding an excess of the appropriate
(C.sub.1 -C.sub.5)alkyl iodide and an amine such as
diisopropylethylamine. The reaction can be conducted at an elevated
temperature for about 4-10 hours. The final product can be purified
by column chromatography.
The invention also comprises the pharmaceutically acceptable salts
of the biologically active compounds of formula I together with a
pharmaceutically acceptable carrier for administration in
effective, non-toxic dose form. Pharmaceutically acceptable amine
salts may be salts of organic acids, such as acetic, citric,
lactic, malic, tartaric, p-toluene sulfonic acid, methane sulfonic
acid, and the like as well as salts of pharmaceutically acceptable
mineral acids such as phosphoric, hydrochloric or sulfuric acid,
and the like. These physiologically acceptable salts are prepared
by methods known in the art, e.g., by dissolving the free amine
bases with an excess of the acid in aqueous alcohol.
In the clinical practice of the present method, the compounds of
the present invention will normally be administered orally or
parenterally, as by injection or infusion, in the form of a
pharmaceutical unit dosage form comprising the active ingredient in
combination with a pharmaceutically acceptable carrier, which may
be a solid, semi-solid or liquid diluent or an ingestible capsule
or tablet. The compound or its salt may also be used without
carrier material. As examples of pharmaceutical carriers may be
mentioned tablets, intravenous solutions, suspensions,
controlled-release devices, microcapsules, liposomes and the like.
Usually, the active substance will comprise between about 0.05 and
99%, or between 0.1 and 95% by weight of the resulting
pharmaceutical unit dosage form, for example, between about 0.5 and
20% of preparation intended for injection or infusion and between
0.1 and 50% of preparation, such as tablets or capsules, intended
for oral administration.
The invention will be further described by reference to the
following detailed examples, wherein melting points were taken
using a Thomas-Hoover Melting Point apparatus in open capillary
tubes, and are uncorrected. NMR data was collected at ambient
temperature on a Bruker AC-200 or a GE Omega 300, using
DMSO-d.sub.6, and TMS as the internal reference. IR data in each
case was obtained from a KBr disk on a Nicollet FT-IR instrument.
Low resolution FAB mass data was obtained on a Finnigan 4000
instrument. Ion spray mass spectral data was obtained from the
Biochemistry Dept. Chemicals were supplied through Aldrich, except
where noted. Naltrexone hydrochloride was obtained from
Mallinkrodt, BOP reagent was obtained from Peptides International.
TLC Rf values were obtained on silica gel using the following
solvent systems: (A) 33% EtOAc, 33% CHCl.sub.3, 33% MeOH, 1%
NH.sub.3 ; (B) 95% CHCl.sub.3, 5% MeOH, 0.1% NH.sub.3 ; (C) 45%
EtOAc, 45% MeOH, 5% NH.sub.3. Analytical data was supplied through
M-H-W Laboratories, Phoenix, Ariz.
Physiological data for guinea pig ileal longitudinal muscle (GPI)
was obtained by the methodology of H. P. Rang, "Stimulant Actions
of Volatile Anaesthetics on Smooth Muscle," Brit. J. Pharmacol.,
22, 356 (1964) on Dunkin-Hartley males; mouse vas deferens (MVD)
data was obtained using Henderson's method on Swiss-Webster males
(G. Henderson et al., "A New Example of a Morphine-Sensitive
Neuroeffector Junction: Adrenergic Transmission in the Mouse vas
Deferens," Brit. J. Pharmacol., 46, 764 (1972). Guinea pig brain
membrane binding assays were done on Dunkin-Hartley males using a
modification of the method of L. L. Werling et al., "Opioid Binding
to Rat and Guinea Pig Neural Membranes in the Presence of
Physiological Cations at 37.degree. C., J. Pharmacol. Exp. Ther.,
233 722 (1985). In vivo assays were done s.c. on mice.
EXAMPLE 1
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-carbo
xy-6,7-2',3'-indolomorphinan hydrochloride (15) ##STR7##
A mixture of naltrexone hydrochloride (2.0 g, 5.3 mmol) and
4-carboxyphenylhydrazine (0.934 g, 6.14 mmol) in 80 mL glacial
acetic acid was stirred at 85.degree. C. under N.sub.2 24-72 hr.
Solid product was removed from the cooled crude mixture by
filtration, washed with glacial acetic acid, acetone, and then
ether. The solid was dissolved in methanol and dried over sodium
sulfate, filtered, and the solvent removed by rotary evaporation,
yielding 15 (1.8 g, 3.6 mmol, 68%). TLC(A) Rf 0.15. MS FAB (M+I)
459. IR COOH carbonyl, 1679 cm.sup.-1.
EXAMPLE 2
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-cyano
-6,7-2',3'-indolomorphinan hydrochloride (7)
Naltrexone hydrochloride (1.0 g, 2.65 mmol) and
4-hydrazinobenzonitrile hydrochloride (3.0 mmol) were mixed in a
minimum amount of glacial acetic acid and 3 drops conc. HCl and
stirred at 85.degree. C. under nitrogen for 72 hr. The cooled
solution was poured into 150 mL ethyl acetate, and the solid was
filtered, washed with EtOAc, then ether, and air dried. Typical
yields of 7 were 50-90%. TLC (A) Rf=0.74; (B) Rf=0.30. FTIR:
nitrile at 2218 cm.sup.-1. MS FAB (M+1) 440.
EXAMPLE 3
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-amino
methyl-6,7-2',3'-indolomorphinan (8)
Nitrile 7 was reduced with H.sub.2 (55 psi) in abs. methanol
containing 10% NH.sub. 3 over Raney Ni for 4-7 days. After
filtering, the solvent was removed on a rotary evaporator, and the
product redissolved in EtOAc and washed 4.times. with alkaline
brine. The combined organic phases were dried on Na.sub.2 SO.sub.4
and MgSO.sub.4, filtered, and the solvent was evaporated. Further
purification was done via silica gel centrifugal chromatography
(Chromatatron) using solvent system (A), when needed. Product 8 was
used as the free base, with yields typically of 40-80%. TLC (A)
Rf=0.25; (B) Rf=0.0; (C) Rf=0.62. MS FAB (M+1) 444. CHN: C.sub.27
H.sub.31 N.sub.3 O.sub.3 Cl.sub.2.H.sub.2).
EXAMPLE 4
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[(N.s
up.2 -acetamidino)methyl]-6,7-2',3'-indolomorphinan dihydrochloride
(3; II, R=CH.sub.3)).
Amine 8 (as the free base, 127 mg, 0.286 mmol) and ethylacetimidate
hydrochloride (39 mg, 0.315 mmol) were dissolved in abs. ethanol
plus 3 drops TEA and the mixture stirred 24 hr at 25.degree. C.
Solvents were evaporated, and the product was dissolved in EtOAc,
and precipitated as the dihydrochloride salt, then recrystallized
from hot EtOH/EtOAc to yield 133 mg of 3 (0.239 mmol, 83%); TLC (C)
Rf=0.15. MS FAB (M+1) 485. CHN: C.sub.29 H.sub.34 N.sub.4 O.sub.3
Cl.sub.2.NaCl.2H.sub.2 O .sup.1 H NMR: 10.06 (bs, 1H, exch); 9.351
(bs, 3H, exch); 9.05 (bs, 1H, exch); 8.911 (s, 1H, exch); 7.405 (s,
1H); 7.387, 7.347 (d, 1H, J=8); 7.162, 7.124 (d, 1H, J=8); 6.718,
6.678 (d, 1H, J=8 ); 6.600, 6.561 (d, 1H, J=8); 6.56 (s, 1H, exch);
5.705 (s, 1H, C.sub.5 .beta.); 4.506 (bs, 2H); 4.209 (bs, 1H);
3.52, 3.408, 3.32 (m, 3H); 3.11 (m, 2H); 3.03 (s, 2H); 2.68 (s,
1H); 2.66 (s, 1H) 2.137 (s, 3H); 1.768 (d, 1H); 1.155 (m, 1H);
0.690 (m, 2H); 0.497 (m, 2H).
EXAMPLE 5
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[(N.s
up.2 -propanamidino)methyl]-6,7-2',3'-indolomorphinan
dihydrochloride (3; II, R=Et)).
Amine 8 (300 mg, 0.677 mmol) and O-methyl propanimidate (molar
excess) were dissolved in abs. EtOH and stirred at 50.degree. C.
until TLC showed no starting material (24 hr). The crude reaction
mixture was concentrated by rotary evaporation and added to brine
at pH 10-11, and extracted with EtOAc. The organic phases were
combined, dried over Na.sub.2 SO.sub.4, and the product
precipitated as the HCl salt, which was recrystallized from
ethanol-ether, to yield 143 of 1, 0.29 mmol, 74%. TLC Rf (A) 0.34.
MS(ion spray) (M+1) 499. CHN: C.sub.30 H.sub.36 N.sub.4 O.sub.3
Cl.sub.2.2H.sub.2 O.NaCl. .sup.1 H NMR: 11.335 (s, 1H, exch);
10.056 (s, 1H, exch); 9.353 (s, 1H, exch); 9.166 (bs, 1H, exch);
8.910 (s, 1H, exch); 7.374 (s, 1H); 7.314, 7.285 (d, 1H, J=8.3);
7.098, 7.070 (d, 1H, J=8.3); 6.593, 6.566 (d, 1H, J=8.1); 6.485,
6.456 (d, 1H, J=8.1); 5.538 (s, 1H); 4.462, 4.453 (d, 2H, J=2. 6);
3.605 (m, 1H); 3.345 (s, 1H); 3.206 (s, 1H); 3.141 (s, 1H); 2.951,
2.934 (d, 1H, J=5.1); 2.84 (m, 1H); 2.804 (bs, 2H); 2.751 (s, 1H)
2.626 (m, 1H); 2.446, 2,422, 2.398, 2.37 4 (m, 2H, J=7.2); 2.353,
2.329 (m, 1H); 1.870 (s, 1H); 1.638 , 1.602 (d, 1H, J=10.8); 1.143,
1.118, 1.093 (t, 3H, J=7. 5); 0.957 (m, 1H); 0.550 (m, 2H); 0.253
(m, 2H).
EXAMPLE 6
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[(N.s
up.2 -3-methylpentanamidino)methyl]-6,7-2',3'-indolomorphinan
dihydrochloride (2, II, R=2-methyl-butyl)
Amine 8 dihydrochloride (200 mg, 0.39 mmol) and a molar excess of
O-methyl 3-methylpentanimidate were dissolved in abs. EtOH with TEA
and stirred at 50.degree. C. until TLC showed no starting material
(24 hr). The residue from the crude reaction mixture was filtered
and washed with small portions of cold ethanol, dissolved in MeOH,
dried over Na.sub.2 SO.sub.4. Product was precipitated as the HCl
salt, and recrystallized from ethanol-ether to yield 69 mg of 2
(0.112 mmol, 29%); TLC (A) Rf 0.48. MS(ion spray) (M+1) 541. CHN:
C.sub.33 H.sub.42 N.sub.4 O.sub.3 Cl.sub.2.1.5H.sub.2 O.2NaCl.
.sup.1 H NMR: 11.384 (s, 1H, exch); 9.954 (s, 1H, exch); 9.243 (bs,
2H, exch); 9.012 (s, 1H, exch); 8.861 (s, 1H, exch); 7.334 (s, 1H);
7.305, 7.281 (d, 1H, J=7.2); 7.098, 7.074 (d, 1H, J=7.2); 6.619,
6.594 (d, 1H, J=7.5); 6.534, 6.509 (d, 1H, J=7.5); 6.477 (s, 1H,
exch); 5.632 (s, 1H, 5C.beta.); 4.474, 4.458 (d, 2H, J=4.8); 4.141,
4.112 (d, 1H, J=8.7); 3.25 (m, 2H); 2.922 (m, 2H); 2.780, 2.768 (d,
1H, J=3.6); 2.605 (dd or q, 1H); 2.20-2.138 (m, 2H); 1.825,
1.805-1.744 (m, 2H) 1.322-1.196 (m, 1H); 1.147, 1.122, 1.106, 1.082
(dd, 2H, J=7.3); 0.834 (m, 1H); 0.822, 0.793, 0.764 (t, 3H, J=8.7);
0.785, 0.765 (d, 3H, J=6.0); 0.586 (m, 2H); 0.387 (m, 2H).
EXAMPLE 7
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[(N.s
up.2 -butyramidino)methyl]-6,7-2',3'-indolomorphinan
dihydrochloride (5, II, R=Pr).
Amine 8 (200 mg, 0.45 mmol) and a molar excess of O-methyl
butyrimidate were heated in 20 mL abs. ethanol at 50.degree. C. for
24 hr with stirring. The solvent was concentrated, and the reaction
mixture was poured into ethyl acetate to precipitate the product.
The product was filtered and washed with ether, then redissolved in
ethanol and dried on sodium sulfate. The product was then converted
to the hydrochloride salt, and precipitated from ether. The
precipitate was recrystallized from ethanol-ether and dried under
high vacuum to yield product 5 (156 mg, 0.27 mmol, 66%). TLC (A) Rf
0.18 (free base), 0.50 (salt). MS(ion spray) (M+1) 513. CHN:
C.sub.31 H.sub.38 N.sub.4 O.sub.3 Cl.sub.2.H.sub.2 O.NaCl. .sup.1 H
NMR: 11.400 (s, 1H, exch); 9.929 (bs, 1H, exch); 9.293 (s, 2H,
exch); 9.242 (bs, 1H, exch); 8.987 (bs, 1H, exch); 8.851 (bs, 1H,
exch); 7.393, 7.350 (d, 1H, J=8); 7.377 (s, 1H); 7.141, 7.098 (d,
1H, J=8); 6.679, 6.639 (d, 1H, J=8); 6.600, 6.559 (d, 1H, J=8);
6.482 (s, 1H, exch); 5.697 (s, 1H, C.sub.5 .beta.); 4.480 (d, 2H);
4.148 (d, 1H); 3.25 (d, 1H); 3.109 (s, 1H); 2.987 (t, 2H); 3.0-2.82
(m, 2H); 2.675 (m, 2H) 2.433 (m, 2H); 2.396-2.307 (m, 1H); 1.828,
1.777 (d, 1H, J=10); 1.680, 1.644, 1.606, 1.569 (quint, 2H, J=7);
1.099 (m, 1H); 0.896, 0.859, 0.822 (t, 3H, J=7); 0.680 (m, 2H);
0.484 (m, 2H).
EXAMPLE 8
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5-[(N.su
p.2 -pentanamidino)methyl]-6,7-2',3'-indolomorphinan
dihydrochloride (6, II, R=Bu).
Amine 8 (200 mg, 0.45 mmol) and a molar excess of
O-methylvalerimidate were heated in 20 mL abs. ethanol at
50.degree. C. for 24 hr with stirring. The solvent was
concentrated, and the reaction mixture was poured into ethyl
acetate to precipitate the product, which was filtered and washed
with ether. The residue was redissolved in ethanol, dried on sodium
sulfate and converted to the hydrochloride salt. The salt was
precipitated from ether, recrystallized from ethanolether and dried
under high vacuum to yield 6 (88 mg, 0.15 mmol, 33%). TLC (A) Rf
0.11 (free base), 0.50 (salt). MS(ion spray) (M+1) 527. CHN:
C.sub.32 H.sub.40 N.sub.4 O.sub.3 Cl.sub.2.1.5H.sub.2 O.NaCl.
.sup.1 H NMR: 11.440 (s, 1H, exch); 10.026 (bs, 1H, exch); 9.315
(bs, 2H, exch); 9.1 (bs, 1H, exch); 8.897 (s, 1H, exch); 7.394 (s,
1H); 7.377, 7.349 (d, 1H, J=8); 7.138, 7.109 (d, 1H, J=8); 6.675,
6.646 (d, 1H, J=8); 6.585, 6.557 (d, 1H, J=8); 5.683 (s, 1H,
C.sub.5 .beta.); 4.505 (bs, 2H); 4.168 (bs, 1H); 3.669 (s, 1H);
3.30 (m, 1H); 3.084 (m, 1H); 3.010, 2.966 (m, 2H); 2.649 (m, 1H);
2.53 (m, 1H); 2.458, 2.434, 2.405 (t, 2H); 2.081 (s, 1H) 1.796,
1.759 (d, 1H, J=11); 1.61-1.55 (quint, 2H); 1.30-1.22 (m, 2H); 1.12
(m, 1H); 0.883, 0.857, 0.833 (t, 3H, J=7.5); 0.70 (m, 1H); 0.63 (m,
1H); 0.48 (m, 1H); 0.43 (m, 1H).
EXAMPLE 9
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[N-(.
beta.-diethylamino)ethylcarboxyamido]-6,7-2',3'-indolomorphinan
dihydrochloride (38)
Compound 15 (200 mg, 0.377 mmol) in 25 mL dry dichloromethane was
brought into solution dropwise with triethylamine. BOP reagent (170
mg, 0.385 mmol) and N,N-diethylethylenediamine (90 mg, 0.75 mmol,
0.1 mL) were added, and the solution was stirred at 25.degree. C.
for 24 hr. The reaction mixture was added to ethyl acetate (150
mL), washed 3.times. with brine at pH 10, and the organic phase
dried on sodium sulfate and magnesium sulfate, filtered, and
concentrated. The residue was converted to the HCl salt using
methanolic HCl and precipitated from ethyl acetate. The product was
recrystallized from ethanol-ether, and dried under high vacuum, to
yield 217 mg of 38 (0.345 mmol, 91%). TLC (A) Rf 0.49; MS(ion
spray) (M+1) 557. CHN: C.sub.33 H.sub.42 N.sub.4 O.sub.4 Cl.sub.2
3.5H.sub.2 O. .sup.1 H NMR: 10.6 (s, 1H, exch); 9.343 (bs, 1H,
exch); 9.032 (bs, 1H, exch); 8.889 (t, 1H, exch); 8.62 (bs, 1H,
exch); 8.106 (s, 1H); 7.778, 7.734 (d, 1H, J=8); 7.413, 7.370 (d,
1H, J=8); 6.699, 6.658 (d, 1H, J=8); 6.613, 6.572 (d, 1H, J=8);
6.57 (s, 1H, exch); 5.705 (s, 1H, C.sub.5 .beta.); 4.152 (d, 1H);
3.644 (m, 2H); 3.527, 3.484 (d, 1H, J=8); 3.190-3.133 (m, 8H as
4(--NCH.sub.2 --)]; 3.024 (s, 1H); 2.679 (m, 2H); 2.586 (s, 1H);
2.43 (d, 2H) 1.831, 1.784 (d, 1H, J=9); 1.262, 1.227, 1.191 (t,
6H); 1.16 (m, 1H); 0.683 (m, 2H); 0.485 (m, 2H).
EXAMPLE 10
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[N.su
p.2 -(N,N-dimethylglycinamidino)methyl]-6,7-2',3'-indolomorphinan
trihydrochloride (42, II, R=CH.sub.2 NMe.sub.2)
Amine 8 (160 mg, 0.36 mmol) and O-methyl
(N,N-dimethyl)glycinimidate (free base, molar excess), were
dissolved in abs. ethanol and maintained with stirring at
50.degree. C. for 72 hr. The solution was concentrated, then poured
into ethyl acetate to precipitate the product. The product was
recrystallized from ethanol-ether, and converted to the
hydrochloride salt to yield 42 (83 mg, 0.13 mmol, 36%). TLC (A)
Rf=0.10, (C) Rf=0.30. MS (FAB) 528 (M+1). CHN: C.sub.31 H.sub.40
N.sub.5 O.sub.3 Cl.sub.3.0.3NaCl.C.sub.2 H.sub.6 O. .sup.1 H NMR:
11.404 (s, 1H, exch); 10.35 (br, 1H, exch); 9,556 (br, 2H, exch);
9,268 (s, 1H, exch); 8.963 (br, 1H, exch); 7,423 (s, 1H); 7,338,
7.309 (d, 1H, J=8.7); 7.163, 7.135 (d, 1H, J=8.4); 6,643, 6.619 (d,
1H, J=7.2); 6,554, 6,525 (d, 1H, J=8.7); 6,505 (s, 1H, exch); 5.652
(s, 1H, C.sub.5 H); 4.567 (s, 2H); 4.161, 4.141 (d, 1H, J=6); 3.471
(m, 1H); 3.402 (s, 1H); 3,353 (m, 1H); 3,297, 3.272 (d, 1H, J=6.3);
3,122, 3.102 (d, 1H, J=6); 3.037 (s, 1H); 2.984 (s, 1H); 2.667 (m,
2H); 2.582 (m, 1H); 2.533 (s, 1H); 2.504 (s, 6H,
N(CH.sub.3).sub.2); 1.812, 1.775 (d, 1H, J=11); 1.142 (m, 1H);
0.715 (m, 1H) 0.634 (m, 1H); 0.524 (m, 1H); 0.439 (m, 1H).
EXAMPLE 11
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[(4-d
imethylaminobutyryl)aminomethyl]-6,7-2',3'-indolomorphinan
dihydrochloride (43)
Compound 8 (as the free base, 179 mg, 0.404 mmol) was combined with
4-dimethylaminobutyric acid (75 mg, 0.444 mmol) and BOP reagent
(200 mg, 0.452 mmol) in dry CH.sub.2 Cl.sub.2 and stirred at
25.degree. C. 24 hr. The crude mixture was poured into 150 mL ethyl
acetate and washed 3.times. with alkaline brine. The organic
portion was dried on Na.sub.2 SO.sub.4, and precipitated as the HCl
salt with methanolic HCl, to yield 82 mg of 43 (0.130 mmol, 32%).
TLC (A) Rf=0.34. MS (FAB) (M+1). CHN: C.sub.33 H.sub.42 N.sub.4
O.sub.4 Cl.sub.2.2H.sub.2 O.0.5NaCl. .sup.1 H NMR: 11,250 (s, 1H,
exch); 10.75 (br, 1H, exch); 9,231 (s, 1H, exch); 8.94 3 (br, 1H,
exch); 8,427, 8.410, 8,390 (t, 1H, J=5.1 and 6); 7.269, 7.240 (d,
1H, J=8.7); 7,167 (s, 1H); 7.001, 6.972 (d, 1H, J=8.7); 6.631,
6.603 (d, 1H, J=8.4); 6.550, 6.521 (d, 1H, J=8.7); 6.395 (s, 1H,
exch); 5,636 (s, 1H, C5H) ; 4.255, 4.238 (d, 2H, J=5.1); 4,141,
4.125 (d, 1H, J=4.8); 3,418, 3,410 (d, 1H, J=5.1); 3,353 (s, 1H);
3.247 (s, 1H); 3.202 (m, 1H); 3.105 (s, 1H); 3,048 (s, 1H); 2.971
(s, 1H); 2,942, 2.930 (d, 1H, J=8.7); 2.650 (s, 6H); 2.585 (s, 1H);
2,195, 2,171, 2,146 (t, 2H, J=7.2 and 7.5); 1,854 (m, 2H); 1,768,
1.732 (d, 1H, J=11); 1,085 (m, 1H); 0,680 (m, 1H); 0.607 (m, 1H);
0.448 (m, 1H); 0.416 (m, 1H).
EXAMPLE 12
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[N.su
p.2
-(4-dimethylaminobutyrylamidino)methyl]-6,7-2',3'-indolomorphinan
trihydrochloride (44, II, R=CH.sub.2 CHhdCH.sub.2 -NMe.sub.2)
Amine 8 (free base, 220 mg, 0.497 mmol) and 0-methyl
4-(dimethylamino)butyrimidate (free base, molar excess) were
dissolved in abs. ethanol and maintained with stirring at
50.degree. C. for 72 hr. The solution was concentrated, then added
to ethyl acetate to precipitate the product. The product was
recrystallized from ethanol-ether and converted to the
hydrochloride salt, to yield product 44 (95 mg, 0.143 mmol, 29%).
TLC (A) Rf=0.0, (C) Rf=0.09. MS (FAB) 556 (M+1). CHN: C.sub.31
H.sub.44 N.sub.5 O.sub.3 Cl.sub.3.1.5H20.0.5NaCl.0.5C.sub.2 H.sub.5
OH. .sup.1 H NMR: (taken as the free base) 11,252 (s, 1H); 7,303
(s, 1H); 7.295, 7.268 (d, 1H, J=8.1); 7.056, 7.029 (d, 1H, J=8.1);
6.561, 6.534 (d, 1H, J=8.1); 6.461, 6,434 (d, 1H, J=8.1); 5.480 (s,
1H, C.sub.5 H); 4.745 (s, 1H); 4,345 (s, 2H); 3.269, 3.250 (d, 2H,
J=5.7); 3,089 (s, 1H); 3.025 (s, 1H); 2.728 (m, 1H); 2.694 (m, 1H);
2,681 (s, 1H); 2,489, 2,467 (d, 2H, J=6.6); 2,408, 2,386 (d, 2H,
J=6.6); 2,293 (m, 3H); 2.157 (m, 3H); 2,052 (s, 6H); 1.601, 1,564
(d, 1H, J=11); 0.883 (m, 2H); 0.488 (m, 2H); 0.159, 0.144 (d, 2H,
J=4.5).
EXAMPLE 13
17-(Cyclopropylmethyl)-6,7-dehydro-4,5.alpha.-epoxy-3,14-dihydroxy-5'-[N-(.
beta.-dimethylamino)ethylcarboxamido]-6,7-2',3'-indolomorphinan
dihydrochloride (45)
Compound 15 (200 mg, 0.377 mmol) in 25 mL dry dichloromethane was
brought into solution by dropwise addition of triethylamine. BOP
reagent (170 mg, 0.385 mmol) and N,N-dimethylethylenediamine (66
mg, 0.75 mmol, 0.08 mL) were added, and the solution was stirred at
25.degree. C. for 5 hr. The reaction mixture was added to ethyl
acetate (150 mL) and washed 3.times. with brine at pH 10. The
organic phase was dried over sodium sulfate and magnesium sulfate,
filtered, and concentrated. The free base was precipitated from
hexane to remove TEA and N,N-dimethylethylenediamine, then
converted to the HCl salt and precipitated from ethyl acetate. The
precipitate was recrystallized from ethanol-ether and dried at high
vacuum to yield 123 mg of 45, 0.204 mmol, 54%. TLC (A) Rf=0.28;
MS(ion spray) (M+1) 529. CHN: C.sub.31 H.sub.38 N.sub.4 O.sub.4
Cl.sub.2l .H.sub. O. .sup.1 H NMR: 11.678 (s, 1H, exch); 10.657 (s,
1H, exch); 9.343 (bs, 1H, exch); 9.030 (bs, 1H, exch); 8.803,
8.787, 8.769 (t, 1H, exch, amide NH); 8.095 (s, 1H); 7.773, 7.746
(d, 1H, J=8); 7.413, 7.370 (d, 1H, J=8); 6.685, 6.657 (d, 1H, J=8);
6.603, 6.577 (d, 1H, J=8); buried, 6.58 (s, 1H, exch, C.sub.14
-OH); 5.700 (s, 1H, C.sub.5 .beta.); 4.163 (bs, 1H); 3.669, 3.649,
3.632, 3.612 (qt, 2H); 3.259, 3.240, 3.220 (t, 2H); 3.28 (m, 1H);
3.089 (m, 2H); 3.034 (s, 1H); 2.988 (m, 1H); 2.88-2.86 (m, 1H);
2.658 (m, 1H); 2.572 (s, 1H); 1.817, 1.784 (d, 1H, J=10); 1.141 (m,
1H); 0.692 (m, 1H); 0.647 (m, 1H); 0.487 (m, 1H); 0.452 (m,
1H).
EXAMPLE 14
Evaluation of Antagonist and Agonist Activity
A. Smooth Muscle Assays
1. Guinea Pig Ileal Longitudinal Muscle (GPI). Ilea from guinea
pigs were taken approximately 10 cm from the ileocecal junction,
and a strip of longitudinal muscle with the myenteric plexus
attached was prepared by the method of H. B. Rang et al., Brit. J.
Pharmacol., 22, 356 (1964). A 1 cm portion of this strip was then
mounted between two platinum electrodes placed in a 10 ml organ
bath and connected to an isometric transducer; contractions were
recorded on a polygraph. Contractions of the ileal strip were
initiated by supramaximal rectangular pulses in all preparations
(80 V of 0.5 ms duration at a frequency of 0.1 Hz). Krebs
bicarbonate solution containing 1.25 .mu.M chlorpheniramine maleate
was the bathing solution and was continuously bubbled with 95%
O.sub.2 and 5% CO.sub.2. The organ bath was maintained at
36.degree.-37.degree. C. The longitudinal muscle strip was allowed
to equilibrate with continuous stimulation for a minimum of 90 min.
Cumulative concentration-response curves were determined after
drugs were added to the bath in preselected amounts and washed out
with buffer after noting their maximum effects.
2. Mouse Vas Deferens (MVD). This assay was performed according to
the description by G. Henderson et al., Brit. J. Pharmacol., 46,764
(1972). Both vasa deferentia were dissected out of mice and mounted
singly through two platinum ring electrodes in a 10 ml organ bath.
The bath contained Krebs bicarbonate solution that was continuously
bubbled with 95% O.sub.2 and 5% CO.sub.2. The organ bath was
maintained at 37.degree. C. The tissue was attached to an isometric
transducer and stimulated transmurally with rectangular pulses (0.1
Mz, 1 ms duration, supramaximal voltage). Drugs were added
cumulatively to the bath in preselected amounts and washed out
after noting their maximum effects.
B. Pharmacology
Each compound (100 nM) was incubated for 15 min with the mouse vas
deferens (MVD) and guinea pig ileum (GPI) preparations prior to
adding graded doses of a standard agonist for determination of an
IC.sub.50 value. The standard agonists employed were [D-Ala.sup.2,
D-Leu.sup.5 ]enkephalin (DADLE) (D), morphine (M), and
ethylketazocine (EK); these are selective for delta (D), mu (M) and
kappa (EK) opioid receptors. Concentration-response curves were
obtained in the absence (control) and the presence of the
antagonist are expressed as IC.sub.50 values. The IC.sub.50 ratio
represents the IC.sub.50 in the presence of the antagonist divided
by the control IC.sub.50 value in the same tissue. Therefore, a
high IC.sub.50 ratio represents a correspondingly high degree of
antagonism at a particular receptor. This IC.sub.50 ratio was
employed to calculate the Ke value using the equation
Ke=[antagonist]/(IC.sub.50 ratio-1). Therefore, a low Ke represents
a correspondingly high degree of binding at a particular receptor.
The results of these bioassays are summarized on Table II,
below.
TABLE II
__________________________________________________________________________
##STR8## Compound number & EK.sup.a (GPI) M.sup.a (GPI) D.sup.a
(MVD) Selectivity structure R=).sup.b Ke.sup.e IC.sub.50.sup.c
ratio.sup.d Ke IC.sub.50 ratio Ke IC.sub.50 .kappa./.mu.
.kappa./.delta.
__________________________________________________________________________
alkyl-amidines: ##STR9## 0.81 nM 124 .+-. 33 8.04 nM 13.4 .+-. 2.2
f 2.81 .+-. 0.62 9 44 ##STR10## 0.66 nM 159 .+-. 43 9.71 nM 11.3
.+-. 2.6 f 2.28 .+-. 0.57 14 69 ##STR11## 0.54 nM 185 .+-. 49 5.84
nM 18.2 .+-. 3.9 f 3.00 .+-. 0.51 10 62 ##STR12## 0.23 nM 439 .+-.
100 6.80 nM 15.7 .+-. 4.0 26.9 nM 4.71 .+-. 1.06 28 93 ##STR13##
0.25 nM 394 .+-. 97 3.27 nM 31.6 .+-. 10.7 f 1.19 .+-. 0.51 12 310
Amide-amines ##STR14## 0.568 nM 177 .+-. 54 3.41 nM 30.3 .+-. 3.6 f
1.51 .+-. 0.42 6 117 ##STR15## (10 nM) 0.320 nM 31.8 .+-. 7.7 (50
nM) 3.14 nM 17.1 .+-. 2.1 (100 nM) f 1.95 .+-. 0.56 16 329
##STR16## 0.505 nM 199 .+-. 62 5.56 nM 19.0 .+-. 6.2 f 1.20 .+-.
0.72 10 166 amidine-amines: ##STR17## 0.183 nM 547 .+-. 125 11.1 nM
10.0 .+-. 0.4 25.6 nM 4.91 .+-. 1.38 55 111 ##STR18## 0.147 nM 679
.+-. 273 9.01 nM 12.1 .+-. 3.4 f 2.71 .+-. 0.44 61 250
norBinaltorphimine 0.56 nM (179) 14 nM (8.14) 14 nM (8.14) 22 22
__________________________________________________________________________
.sup.a Agonists: kappa (EK) (ethylketazocine) mu (M) (morphine)
delta (D) (DADLE) .sup.b All antagonist concentrations were 100 nM
except where noted. .sup.c IC.sub.50 = conc. of drug producing 50%
inhibition of maximum response. .sup.d IC.sub.50 ratio = IC.sub.50
agonist + antagonist/IC.sub.50 agonist .sup.e Ke =
[antagonist]IC.sub.50 ratio1. .sup.f The Ke value cannot be
determined because the IC.sub.50 ratio is not significantly
different from 1.
The compounds tested showed little or no agonistic activity in
either the GPI or MVD preparation. However, the compounds showed
significant antagonistic potency toward the kappa opioid receptor
agonist, ethylketazocine (EK), in the GPI. This was manifested by
displacement of the EK concentration-response curve to higher
concentration by factors up to 680 (IC.sub.50 ratio) in the
presence of 100 nM of the test compounds. These results contrast
with the observation that these compounds are considerably less
effective in antagonizing the effect of morphine (a mu
receptor-selective agonist). In this connection, it can be seen
that the morphine IC.sub.50 ratios at the same concentration of
antagonist (100 nM) are not greater than one-sixth of those
IC.sub.50 ratios obtained with EK. Likewise, the EK results
contrast with the observation that these compounds have
considerably less ability to antagonize the activity of DADLE
(delta-receptor agonist) at the same antagonist concentration (100
nM). This is demonstrated by IC.sub.50 ratios not greater than
one-thirtieth of those ratios obtained with EK. Thus, the compounds
are highly selective kappa-opioid receptor antagonists. Compounds
2, 5, 6, 38, 42, 43, and 44 are all more potent than the most
potent known kappa antagonist, norBNI (norBinaltorphimine), and of
these, 6, 42, and 44, are also more selective. Of these compounds,
it appears that 44 possesses the greatest potency and
selectivity.
Compound 6 was tested in vivo using the mouse writhing procedure of
G. Hayashi et al., Eur. J. Pharmacol., 85, 163 (1982). It is
believed that this response is mediated by kappa receptors. Mice
were treated with 50 nmol of the agonist (morphine, DADLE, or the
kappa selective agonist U50488H) and the 6 was administered
subcutaneously (sc) at 4 mg/kg. The ED.sub.50 ratios
[(agonist+6)/agonist control] for morphine, DADLE, and U50488H,
respectively were 1.63, 0.25, and 3.77. Therefore, the observed
inhibition exhibited by 6 of the writhing inhibition of morphine,
DADLE, or U50488H in the whole animal model correlates with that
observed in vitro, and demonstrates that 6 is indeed a selective
kappa antagonist.
C. Discussion
The 5'-substituted naltrindole compounds listed on Table II display
a unique pharmacological profile in that they exhibit substantially
greater antagonist potency at kappa-opioid receptors than at mu or
delta opioid receptors. Moreover, compounds 6, 42, and 44 are more
potent and selective than the selective kappa antagonist, norBNI.
The in vivo antagonist selectivity parallels that observed in the
GPI preparation. Because these compounds exhibit no agonist effect
in GPI or MVD, these can be regarded as "pure" kappa opioid
receptor antagonists. Therefore, compounds 6, 42, 44, and the other
compounds of the present invention which exhibit kappa opioid
receptor antagonist activity should be useful for pharmacological
studies of opioid receptor activity and function and may be
therapeutically useful in conditions where selective blockage of
kappa receptors is desired. This includes blockage of the appetite
response, blockage of paralysis due to spinal trauma, and a variety
of other physiologic activities that may be mediated through kappa
receptors.
All publications, patents and patent documents are incorporated by
reference herein, as though individually incorporated by reference.
The invention has been described with reference to various specific
and preferred embodiments and techniques. However, it should be
understood that many variations and modifications may be made while
remaining within the spirit and scope of the invention.
* * * * *